Typewriting machine



Aug. 9, 1938. l R. G. THoMPsoN l v 2,126,356 TYPEWRITING MACHINEFiledvFeb. 2o, 1957 ATTORNEY Patented ug. 9, 1938 PATENT OFFICETYPEWRHTHNG MACHINE Application February 20, 1937, Serial No. 126,902

17 Claims.

This invention relates to typewriting machines and with regard tocertain more specific features thereof, to a carriage mounting anddistance regulator for such machines.

The invention has a particularly useful application to noiselesstypewriters of the character involving a controlled thrust or pressureof the type bars toward the platen, as distinguished from. machines inwhich the writing is effected l0` by uncontrolled impact of the typebars on the platen.

In noiseless typewriters the type heads are given their final movementtoward the paper on the cylindrical platen by hammers, sometimes calledmomentum accumulators and each type bar moves to a fixed printing planeand exerts a typing pressure within the range of approximately l5 to 25pounds. Difficulty has been experienced in obtaining a sharp and uniformwrite and good manifolding results and this is due in large part to thefailure of the platen to resist the normal type-action pressures. Someor all of the imprints are blurred and the rearlward yield of the platendestroys the full typepressure effect and limits the number of legiblecopies.

Not only does the platen yield rearwardly under type-bar pressures butit has a tendency to yield laterally or twist when the carriage is`moved rapidly to a distant stop and this, in accentuated cases,produces a banking-over of the platen carriage at the left margin of themachine. When this happens the rst letter of a line of typing ispositioned in advance of the first letters of previous lines, and theregularity of the left margin of the sheet is destroyed.

The objectionable features above stated are believed to be due in majorpart to the construction and mounting of the center tie of the ma-40chine which is slidably mounted in ways machined in a cross bar of theframe and in a comb attached to said cross bar. Under the most carefulmachining obtainable with reasonable tolerances to suit commercialpractice the slide mounting allows a slight fore-and-aft rock and alateral twist of the center tie. An arm upstanding from the rear of thecenter tie is depended on to'resist rearward movement of the platen andthis resistance is oifered in the rst instance with the movementsallowed by the slide clearances to the end that rigidity of the centertie is lacking.

That these difculties have been recognized is evidenced by the fact thata complicated series of adjustable stops has been employed to set thecenter tie up as closely as it is possible to do so and still permit thesliding movement of it to regulate the distance of the platen in respectto the printing plane. This distance regulation is deemed necessary forthe accommodation of varying numbers of sheets around the platen. If asingle sheet is to be typed the carriage and its platen are setforwardly to suitably present the sheet to the type bar at the end ofits stroke where its pressure is predeterminately correct for imprint.If several copies are to be made the carriage and its platen must be setrearwardly so that the outermost sheet on the platen will not be undulyadvanced into the Xed path of movement of the type bar and thus Vary thepressure to the sacrifice of good writing and maniiolding.

In machines employing the slidable center tie a series of curved springsare mounted on the cross bar of the main frame at either side and theirfree ends bear on the center tie to urge it rearwardly. An eccentricoperated from a handie at the front or side of the machine is used tourge the center tie forwardly in opposition to these springs. Thus thenecessary fore-and-ait adjustment of the center tie and the platencarried thereby is obtained. clearances must not be too greatly reducedby any set-up screws or other adjustments or the springs must fail toperform their function.

So it has become a matter of extremely nice adjustment of set screws tominimize the foreand-aft rock of the center tie, and of other adjustingdevices on either side of the upstanding arm to minimize the lateraltwist, and at the same time leave a capability of bodily adjustment ofthe center tie toward and from the printing plane. Certain of theadjusting devices are set up to hold with a small surface friction andafter carefully making them at the factory as a necessary precedent totest they must be immediately remade in the eld after transportation ofthe machine. If the machine receives any considerable shock in use theseadjustments must be made again by someone experienced in typewriterservicing. The making and remaking of these adjustments adds greatly tothe cost of manufacture, marketingand maintenance of the machine.

Obviously the slide The invention has, therefore, for one of itsobjects, to provide a machine securing better writing and manifolding,which machine may be produced and maintained with less expense.

It is another object of the invention to provide a means of avoiding thepreviously described marginal banking-over of the carriage.

It is another object of the invention to eliminate the necessity forfrequent adjustments and provide a machine which may be subjected to therigors of transportation and delivered in the field without necessityfor adjustments by the consignee.

The invention accordingly consists in the various features ofconstruction, combination of elements and arrangements of parts whichwill be exemplified by the description of a preferred form of theinvention hereinafter set forth and the scope of the application ofwhich will be indicated in the appended claims.

In the accompanying drawing wherein is shown one of various possibleembodiments of the inventiont- Fig. 1 is a view in right side elevation,broken at the rear into vertical central section, of a type- Writingmachine embodying the improved carriage mounting and distance regulator.

Fig. 2 is a view in top plan of the carriage mounting and distanceregulator shown in Fig. 1.

Fig. 3 is a view in rear elevation of the typewriting machine shown inFig. 1, with a part of the rear plate broken away to show more clearlythe carriage mounting means, and

Fig. 4 is a fragmentary View in side elevation of the upper portion ofthe rear plate showing the means for opposing return and tabulatingmovements of the carriage.

Referring now more particularly to the drawing a main frame is indicatedat 3D having a left side wall 3| and a right side wall 32. Projectinginwardly from these side walls are spaced lugs 33 to which are secured,by dowel pins 34 and screws 35, the lower ends of substantially flatsheet metal springs 36.

The lugs 33 on each side wall are spaced apart preferably on an angle of10 from the horizon.- tal, as shown in Fig. l of the drawing, andsprings 36 extend upwardly in parallelism from the front face of theforward lug and the rear face of the rear lug at right angles to thealignment of the lugs fore-and-aft of the machine. Thus two sets ofspring supports are provided, one at each side of the machine.

Across member indicated generally at 40 is preferably a casting having alateral plate portion 4| terminating in somewhat enlarged ends 42 and43, and these ends have their front and rear faces machined to fitbetween the upper ends of the springs 36 of each set and be securedtherein by dowel pins 44 and screws 45. Thus the cross member 46 issecurely held in position within and between the side walls of the framewith a capability of fore-and-aft movement owing to the resilience ofthe springs 35.

The cross member 40 has a central upstanding arm 46 at the rear thereofpreferably cast integral with the cross plate 4|. In the region of anelbow 41 spaced webs 48 extend rearwardly and turn outwardly at theextreme rear to form flanges 50 to which is secured a tabulator casingThe webs 48 continue upwardly reinforcing the arm 4G and defining achannel in cross section of the upper part of said arm.

The cross plate 4| is provided with upstanding ears 52 at each of itsends 42-43 and each ear has threaded therethrough a pivot screw 53 forpivotally supporting a case-shift or balancing frame indicated generallyat 54. The frame 54 is in the form of a cast cross bar 55 with enlargedends 56 to the outer faces of which are xed adjustable platescorresponding to the one shown in Fig. l at 51. Rearward extensions 58at opposite ends of the case-shift frame are pivotally connected withears 68 depending from a track 5| which supports a carriage rail 62 fortransfer movement on suitable anti-friction rollers indicated at 63. Thecase-shift frame 54 may be moved pivotally on screws 53 to raise thecarriage to upper case position by either manually operated or manuallyselected power driven means and in its movement it may be suitablycounterbalanced by conventional spring means not shown. Adjustable stopmeans indicated generally at 64 limits the upper case throw of thecarriage and adjustable stop means indicated generally at 65 limits thelower case position of the carriage.

A carriage is schematically indicated in Fig. 1 of the drawing and hasthe usual oppositeend frame members 1| to which is secured a rigid bar12. This bar and the carriage bar 62 complete the carriage frame and aroller platen 13 is journaled in the opposite ends 1| of the frame.

The upper end of the upstanding arm 46 of cross member 40 has a verticalcentral slot 15, and a sheet metal angle member 16 having acorresponding slot 11 is iitted over the upper end of arm 46 and securedin position thereon by screws 19 which also secure a bridge 18 to therear of said arm in the channel heretofore referred to as being formedby the continuation upwardly of webs 48. The front face of angle member16 has a finished surface against which rail 12 of the carriage slidesboth in the transverse movement of the carriage and in the up-and-downcase-shifting movements thereof. The rail is guided in these movementsby an organization of parts comprising an angle member 88 having a reardown-turned end 8|.

A bolt 82 passes rearwardly through a washer 83, a slot 84 in thedown-turned end 8|, a square nut 85 arranged in slot 11, a clip 86, aWasher 81 and a nut 88. The rear end of bolt 82 is slotted for rotationof the bolt in nut 85 which latter is loosely but non-rotatively fittedin slot 11. To adjust the angle member 80 toward and from the face ofangle member 16 the nut 88 is loosened by a hollow socket wrench and ascrew-driver is inserted through the wrench to turn bolt 82. When theproper adjustment is obtained the bolt is held by the screw-driver andthe nut 88 is turned up tight by the socket wrench.

The clip 86 bears against the rear face of angle member 11 and has aforwardly-turned upper end 90 which projects through slot 11 andoverhangs the rear edge of the rail 12. A stud 9| secured to the frontcenter of the angle member 80 has a flange 52 which overlies the forwardupper edge of rail 12. Thus the adjusting device is supported at thefront and rear of the rail. Suitable anti-friction rolls 93 on the anglemember 80 bear loosely against the front edge of the rail and as thebolt is adjusted in one direction these rollers urge the rail againstthe front face of angle member 16.

Thus it will be seen that the carriage rail 12 is tied to the upstandingarm of the cross member by means which maintain this relation throughoutthe case-shifting movements of the rot carriage and throughout thecarriage transversing operations.

j A rigid back plate 94 is attached to the rear ends of the oppositeside walls as indicated at .95,and 'rises to La position approximatelyopposite the top of the roller platen I3. In the up-per portion of thisback plate an adjusting screw 9S is threaded to abut the point of thescrew against the bridge 18 on the arm 16. The screw has a knurled head97, the inner face of which has a circumferential series of spacedindentations 98 adapted to be engaged by a spring-pressed detent locatedin the rear ofthe upper portion of the back plate. Around the peripheryof the screw head are numerical indications corresponding to the numberand-position of the indentations 98 (see Fig. 4). The adjusting-screwhead has a top |0| which limits its rotation to slightly less than 360byjengagement with the detent |00. Thus it will be seen that the axialmovement ofthe adjusting screw is limited to substantially the pitch ofone thread and that this movement may be dividedY into a multiplicity ofincrements inrotating the knurled head to present one indentation 98after another to the detent Hill." By this means the cross member 46 maybeiZ moved forwardly `a very limited extent to advance and will carrywith it the carriage rail 12 and the entire carriage frame and theplaten mounted thereon so that the platen will be advanced toward theeXtreme of movement of the type bars, one of which is indicated at m2 inFig. l,',or, in other words, toward the` printing plane. It is to benoted that the rigid back plate 94 carries the screw 9B at a pointapproximately opposed to the direction of thrust of the type bar andthat the carriage rail 12 is in approximately this line of thrust. Forpurposes of visibility this line is at an angle of 10 degreesinclination from the horizontal and the adjusting screw S6 and the rail'l2 are both adapted to this inclination. The lugs 33 on the side wallsof the frame are so shaped and positioned that the flat springsupporting members must be exed forwardly approximately elle when theadjusting screw Se is advanced to its most forward position. Thus theentire carriage support is under a constant bias rearwardly forcing thebridge 18 at all times against the end of the adjusting screw Sii.Therefore as the screw is turned in a direction to cause retreat of itsend the springs 36 continuously urge the carriage arm into engagementwith the end of the screw. When it is desired to accommodate a largenumber of copies on the platen the adjusting screw is let oif to desiredposition and the springs 36 cause a retreat of the carriage from theprinting plane.

The springs 36 are preferably of steel about 3" in height by 1l wide by.04 thick and as supported andengaged with the cross member providesubstantial opposition to torsion, but in order to further reinforce theupstanding arm of the cross member spaced ears |03, which are cast onthe forward face of the back plate at the upper portion, embrace theupper end of the upstanding arm 46 and are provided with inwardlyprojecting threaded members H34 having flanges |05 which bear againstsheet metal keepers |06 secured to opposite sides of the arm by screws|l!'|, the Shanks of which pass through slots |08 in the keepers andthread into the webs 48 of the arm. Each keeper is provided with afore-and-aft slot Ill] extending forwardly from the rear edge of thekeeper, and in these lslots are located ends I I2 which project beyondthe flanges |05 of the screw members |04.

By the above described means tabulator and carriage return shocks aresubstantially opposed yet fore-and-aft adjustment oi the cross member ispermitted by the slot ||0 by reason of the fact that the screw membersare set up to bring the iianges |05 very lightly against the keepers|06.

By the above described relatively inexpensive construction the rollerplaten 13 is rigidly held to resist type bar pressures and the shocks oftabulation and carriage return on the upstanding arm 46 are stoutlyopposed. The first writing on the paper is extremely sharp, clear anduniform, and a large number of carbon copies can be satisfactorily made.As the sliding mounting of a center tie is eliminated all clearancesconsequent thereto are eliminated and accordingly the necessity for niceadjustments to minimize these clearances is eliminated, thus doing awaywith the expense of making these adjustments at the factory, remakingthem in the field and making them from time to time to maintain themachine in appropriate working condition.

Vihat is claimed isi- 1. In a typewriting machine, platen-carriagesupporting means comprising, a spring-supported cross-member, acase-shift frame pivoted on the cross-member, a carriage-supportingtrack on said frame, and a platen-carriage on said track.

2. In a typewriting machine, platen-carriage supporting meanscomprising, a main frame, upstanding spring pieces fixed to the mainframe, a cross-member fixed to the upper ends of said spring pieces,case-shifting means pivoted on the cross-member and including a track,and a platencarriage on said track.

3. In a typewriting machine, a platen-carriage support comprising, amain frame, spaced sets of substantially parallel leaf springs securedto the frame, a cross-member xed upon the upper ends of the springs ofeach set, and a platen-carriage pivotally Ysupported by saidcross-member for case-shifting movement. v

4. In a typewriting machine, a platen-carriage support comprising, amain frame having side walls, a set of upstanding substantially parallelleaf springs inside each side wall, each spring having its lower endsecured to the frame, a cross-member having its opposite ends fixed tothe upper ends of the springs of each set, and a platen-carriagesupported on said cross-member.

5. In a typewriting machine, a main frame having side walls, .a set ofupstanding parallel springmetal members supported by the side walls ofthe machine, a cross-member held on the upper ends of the spring sets, acase-shift frame pivoted on the cross-member, a carriage track on thecaseshift frame, a carriage on the track, anti-friction bearings betweenthe track and carriage, and a cylindrical platen journaled in saidcarriage.

6. In a typewriting machine, a main frame, a platen-carriage havingspring supports which bias it rearwardly, and an adjustable abutmentrearwardly of the platen-carriage for moving said carriage forwardly todifferent adjusted positions against the action of said'spring supports.

7. In a typewriting machine, a main frame, a platen-carriage havingparallel spring supports which bias it rearwardly, and an adjustableabutment rearwardly of the platen-carriage for moving said carriageforwardly to different adjusted to said track, a cross-member, uponwhich said upstanding spring pieces having ends secured to positionsagainst the action of said spring supports.

8. In a typewriting machine, a main frame having an adjustable abutment,a platen-carriage having two sets of parallel spring supports, one ateither side of the machine, which'spring supports bias theplaten-carriage rearwardly against said abutment, and means for movingsaid carriage forwardly to different adjusted positions against theaction of said spring supports.

9. In a typewriting machine, a main frame having side walls and a backwall, a platen-carriage having end walls and having a track bar and arail between the carriage end walls, a track for said carriage, acase-shift frame connected case-shift frame is pivotally mounted, havingan arm extending upwardly, a pair of substantially parallel leaf springssecured to the main frame inside each side wall with their upper endssecured to the` cross-member, and an adjusting device in the back wallof the main frame behind the carriage railfor forwardly moving theupwardly extending arm.

10. In a typewriting machine, a main frame,

said frame, a cross-member having its ends secured to the other ends ofsaid springs and having an upwardlyv extended arm, a carriage supportedby said cross-member, a platen on said carriage, a rail on said carriagebearing against the upwardly extended arm of the cross-member, and meansfor adjusting said arm forwardly against the action of said springs.

11. In a typewrit'ing machine, a main frame having side walls and a backwall, upstanding substantially parallel leaf spring sets xed adjacenteach side wall, andy having free ends, a cross-member secured tothe freeends and biased rearwardly by the springs, a case-shift frame on thecross-member, a supporting track, a carriage slidably mounted on saidtrack, a roller platen journaled in said carriage, a rail on saidcarriage, an arm on said cross member against which the rail bears, andmeans on the back Wall for adjusting the cross-member forwardly.

12. In a typewriting machine, a main frame having a rear wall, across-member, spring means for supporting said cross-member from saidframe, said cross-member having an upstanding arm at the rear of themachine, a platen-carriage pivotally supported on said cross memberhaving a rear rail bearing against the upstanding arm, and means formaintaining the relation of the rail and arm during case shiftingOperations.

13. In a typewriting machine, a main frame having side walls and a rearwall, a platen-carriage, iiexible supporting means for saidplatencarriage, an adjustment device supported in the rear wall adaptedto resist rearward movement of the carriage and to be moved to adjustthe carriage in a forward direction.

14. In a typewriting machine, a main frame having side walls and a rearwall, a platen carriage having arail, parallel motion means forsupporting said platen-carriage, 'and means in the rear wallapproximately directly behind the rail for moving the carriage forwardlyon said sup-- porting means to different positions of adjustment.

15. In a typewriting machine, a main frame having side walls and a rearwall, a platen-carriage having a rail, springs supporting saidplaten-carriage adapted to bias it` toward the rear wall, means in therear wall approximately directly behind the rail for moving the carriageforwardly against the action of said springs to different positions ofadjustment, and types movable to a printing point substantially in linewith said rail and said carriage moving means.

1G. In a typewriting machine, a platen, a frame, and upstanding spacedparallel spring members adapted to support the platen on the frame withcapability of adjustment relative to the printing plane.

17. In a typewriting machine, a platen, a frame, and upstanding spacediiat sheet-metal parallel spring members adapted to support the platenon the frame with capability of adjustment relative to the printingplane.

RUSSELL G. THOMPSON.

